Stencil printing machine



March 26, 1935. H. H. STOELTING STENCIL PRINTING MACHINE Filed Oct. 10, 1932 4 Sheets-Sheet l 11v ENTOR March 26, 1935. H, sTOELTlNG 1,995,403

STENCIL PRINTING MACHINE Filed Oct. 10, 1932 4 Sheets-Sheet 2 I INVENTOR Mal 'ch 26, 1935. s fm 1,995,403

STENCIL PRINTING MACHINE Filed Oct. 10, 1952- 4 Sheets-Sheet 5 March 26, 1935. H. H. STOELTING 7 1,995,403

' STENCIL PRINTING MACHINE FiledOct, 10, 1932 4 Sheets-Sheet 4 k INVENTOR Patented Mar. 26, 1935 UNIT-ED. sTA-T Es PATENT fo FicE STENCIL PRINTING MACHINE HugoH. Stoelting, Cleveland; Ohio Application October 10, 1932, Serial s am;

19 Claims. (c1.101 125) This invention relates to stencil printing machines andparticularly to a rocking-motion or cradle-type machine with mechanism to control the position and alignment of the stencil repro- .ductions onmultiple copies.

The principal object of my-invention is to" provide means for the commercial production of a light and comparatively inexpensive stencil printing machine, which may be carried like a portable typewriter, simple and easy to operate, with provision'for fixing the positionand alignment of the stencil reproductions on successive copies-l Afurther object is to devise means for attaching an ink pad. in said stencil printing. machine. Another object is to devise means for attaching a stencil in said machine. Still an'-' other object is to devise means forguiding and aligning paper in said machine.

The foregoing and other objects are obtained by the devices illustrated in the accompanying drawings and described below. It isto be understood that the device is not limited-to th specific form thereof disclosed herein. 7

Of the accompanyingdr'awingsf Y Figure 1 is a schematic side elevation of a stencil printing'machine embodying the inven-' tion;

Figure 2 is a diagrammatic side elevation of the machine illustrating the path of movement of the various parts thereof;

Figures 3 3 S 'an'd 3 are detail' sections of 'a portion of the machine illustrating the method of attaching the' ink pad. and stencil; l

Figure 4 is a perspective detail of a paper guide used in the machine; v

Figure-5 is a side elevation of a modified form of the machine; 7

Figure 6 is a side elevation of the machine i1-' lustrated in Figure 5, with the parts closed and a cover applied thereover; I V

Figure 7 is a side elevation, partly broken away-or" the machine shown in Figure 5, illustrating the lid raised to permit ink or a .stencil tobe applied;

' Figures 8 and 9 are perspective details of the forward and rear portions of the modified form of machine shown in Figure 5; a

Figures 10 and 11 are perspective views of two further modified forms of the machine;

' Figures 12 and 13 are perspective views, partly broken away, of further modified forms of machines embodying theinvention.

Referring in detail to Figure 1 of the drawings, the numeral 15 denotes the base of the machine 'upon; which are attached a pair of lugs 16..

relative position with respect to platen'23.

Links 17 are pivoted at 18 at one end thereof to lugs 16 and acover' or top plate'19 isinturn pivotedat 20 at'its rearward portionto the other ends of links 1.7.- The forward portion of the top plate l9 has pivoted thereto at'21 a pair of rockerarms 22 formed with an arcuate stencil platen 23 between'and beyondsaid arms. A pair of connecting 'bars24 arepivoted at 25 to arms 22 and at 26 to links 17. Links '17, arms 22, bars 24 and top plate'19 are pivoted similar to a parallel bar arrangement but as diagrammatically illustrated in Figure '2 do not move as a shown in dotted lines in Figure 2 during the rocking movement of platen 23. Owing to the fact that the parts above mentioned do not move as a true parallelogram there is a tendency for slight relative motion "between the platen 23 and the 25 base 15 toward the ends of the arc; Provision is made to avoid such relative movement by forming slots 28 in bars 24 at pivot points 26'to afford a slight lostmotion between bars 24 and links 17. This slot to provide lost motion may be placed at any-of the other pivot points as will be later described. Hooks 29 on the extended ends of bars 24 may be engaged-with a hook 30 at- I tached to base 15 whereby platen 23 may be re- .tained in a raised'p'osition while the machine is not in operation.

The cover or top plate'is provided with a knob or handle 31 by which the device may be operated 34 passing through a slot 35 in base 15. An angular guide member 36 has one arm thereof slidably engaged under clamp member 32. Since the paper guide parts are slidable fore and aft and laterally and mayalso be pivoted about screw 34, the paper 37 may be guided into any desired Platen 23 is provided with a plurality of perforations 3'? whereby ink applied to the back of the platen will penetrate therethrough and become absorbed in a. felt or fabric pad 38 attached to the outer surface of platen-23 bymeans of a fabric band 39. Band 39 is provided at its ends with fastening means 40 which extend across the width of band 39 and clamp same against a I attachment to base 15*.

., respect to the .top plate.

chine is illustratedwitha cover 56 which may be in Figures 3? and. 3 the cardboard tab 45' on the end of the stencil being bent asshown and being clamped into place by a channelmember 46 carried by a'pair of spring-pressed;lever arms 47 pivoted to rocker arms 22. The other end of the stencil may be clamped to the-platenirr like manner.

In the modified form of the invention shown in Figure 5 like-parts of the-.machine "bear.;the same reference numeralsasthose of Figure l with the exponent 'a. Inthisform of -the;machine the slot. 48 for affording lost motion is formed the,

forward end of bars 24*. .1 Bars 24* are connected at the rear of the machine by a bar 49 which may be engaged with hook-30? to retain the platen in raised position as shown'in Figuresb, '7 and 9.

Lugs 18 and hook 30 may be made integral for The rear portion of the machine is braced againstdistortion by connect-.

ing links 17 acrossthe bottom as shown in Figthereto a reinforcing bar 50. 1

Top plate 19? is detachably secured to links 51 attached to rocker'arms 22, by means of springure 9 and byv riveting or otherwise attaching:

pressed detents 52' which may be .engagedlby knobs 53 to release the top plate when the platen is to be inked or the stencil is tobe' changed as.

shown in Figures 7 and 9. When the top plate 19 is again to be connected to the rocker arms it is' snapped into place over the detents. 52, 52,-...the.

latter being guided'into their, seats 54 by means of guide flanges 55which extend diagonally with applied over the machine, as illustrated in Figure 6 and retained in place by springepresseddetents 57,57. In order to remove the operating knob 31 from its normal position and tolock the parts in fixed position when the; cover is in place, knob be swung around in'the; position shown in Figure Sand engaged ,by the forwarddetent 57..

. The machine is thus very compact 'when not in use.

In the modified form of the machine shown in Figure 10, parts similar to"the' .foregoing, form. of the invention aremarkedwith-the same nu--;.

In place of the knob 31 is attached to a U-shaped member 63 which is afiixed tothe sides of} platen 23h Thelatter may be provided with agcover plate 64' to;

guard; against the ink'being thrown from the interior of the platen; j 1- p In the modified form of :themachineshown. in

Figure 11 the parts are: similar tocthose of the formvshownimFigure' l and:.are:.similarly.de-.-

This form of theme-- In this 7 form of the device the slot 6l'for affording lost motion is formed in bars 59 at the upper pivots Links-17 and their top portions are con-, nected by a reinforcingb'ar 62. The operating noted by numerals with the exponent c. In this form of the device the platen is made entirely detachable from the parallel bar mechanism and is secured thereto by means of screws 65 attached to member 63 and engageable in slots 66 formed in yoke member 67 to which are connected parallel bars 59 and 24.

In the form of the device shown in Figure 12 the device is similar to that of the forms shown in Figures to 9 inclusive but has been modified as to themanner of engaging the detent with the top plate. In this form of the device the ends of spring-pressed detents 52 are engageable directly in apertures 68 in top plate 19 A modified form of means for clamping the stencil in position is also shown. This consists of pivot arms v 47? attached to the ends of channel members 46 springs 69 being attached to the front and rear lever arms 474 for yieldingly clamping the channel members 46 against the platen.

Figure 13 illustrates a modified formof pivoted connection for connecting the top plate 19 to the base .15 This connection is made through a plate 70 respectively hinged at 71 and 72 to the top plate and to a plate 73 attached to base 15. A hook device 30 is formed integral with plate 73 for engagement with hook74 attached toxthe top plate for retaining the platen in raised position.

,Inthe operation of the stencil printing machine-theink pad and band 39 are assembled with the platen asheretofore described and inked from the back side of the platen. The stencil is applied as above mentioned by creasing or folding thecardboard tab. The latter may be provided with perforated line across the cardboard for determining the position of the crease. The crease thus serves as a guide for the proper alignment of thestencil after the tab has been clamped by. channel member 46. One or more sheets of paper may then be placed on the base against guide bar 36 and printed upon by bringing the platen into engagement with the paper at one end of the arcuate portion thereof and rocking the platen over the paper until the other end of the platen is engaged with the paper. The

.platen is then raised, the top sheet of paper removed and the platen returned to its original position while raised, the lost motion being taken up on the same end of the stroke as each sheet is printed. If desired, however, one sheet may 31 is attached to a hinged plate 5.8 which-may,v

be printed as the platen is rocked in one direction while the succeeding sheet is printed while the platen is rocked in theopposite direction. The parallel bar arrangement insures that the platen .willbe retained in alignment and in the same relative position with respect to each printed sheet.

of the pivot points of the .parallel bar arrangement; this may be dispensed with where the arc 'of the platen subtends a relatively small angle.

In the use of the form of the invention illustrated in Figure 11 the platen may be entirely detached from the parallel bar mechanism and used as a simple hand stenciling platen if desired. The embodiment of the inventiondisclosed hereinis to be taken in a descriptive and not a limiting sense, accordingly various modifications of the invention may be resorted to without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1'. The combination with a base plate, of a curved platen, means for mounting an ink pad on the convex surface of said platen, means formounting a stencillover the. surface of said pad;

means whereby said stencil may be brought into contact with a sheet of paper placed on said baseplate, so as to cause a :print or reproduction of said stencil to be made-on said paper as a rocking motion is imparted to the platen, andmeans comprising a parallel bar mechanism between said platen and said base platewhereby positive duplication of position of: successive stencil prints 'or reproductions .on said copy'paper may be-made;

2. The combination with a platen, of means for mountingthereon a stencil having a cardboard tab attached thereto; said stencil being adapted to be formed'with a transverse crease or fold extending at right-angles to the side margins of the stencil, said means comprising a transverse spring-pressed channel member extending at right angles to the side margin of said platen and adapted toengage said crease orfold in the tab on said stencil for clamping same to the end of said platen, whereby said stencil will be aligned rocking motion platen for stencil printing on a sheet of paper on said base plate, a parallel bar mechanism connecting said platen to said base plate, and means on said base plate for adjustably guiding the position of said paper with respect to said base plate for adjustment of the alignment of the stencil-print on said paper.

ing motion platen for stencil printing on a sheet of paper on said base plate, a parallel bar motion control mechanism connecting said platen and said baseplate, and means affording lost motion in said parallel-bar control mechanism to permit said platen to said base plate whereby the position of the stencil print or reproduction produced by said printing platen will be fixed with respect to said base plate, and means for guiding a stack of paper on said base plate in a fixed position with respect thereto so that successive sheets of said stack of paper will be identically aligned and positioned as each sheetof paper is printed and removed in turn.

7. The combination with a base plate, of a stencil printing platen, and-a parallel bar mech-[ anism connecting said platen to said base'plate.

8. 'The combination with a' base plate, of a stencil printing platen, means for mounting an ink pad and stencil on the convex surface of said platen, a parallel bar mechanism for linking said printing platen to said base plate.

9. A duplicating machine comprising a base, a pair of lugs afiixed to said base, a pair of links having one end of each thereof pivoted to one of said lugs, a printing platen having an arcuate printing surface, said platen being mounted to move over said base with a rocking motion and adapted to have an ink pad and stencil attached thereto, a pair of arms formed on the sides of said platen, a pair of bars pivotally connected to the ends of saidarms and to the ends of said links remote from the ends thereof pivoted to.

said lugs, and asecond pair of bars substantially parallel to said first-named pair of bars, said second-named pairof bars being pivotally connected at one end of each thereof to the arms on said platen intermediate the'arcuate face and' the end portions thereof, the other of each of the ends of said second-named pair of bars being pivoted to said links intermediate the end portions thereof, said linksQsaid arms and said first and second-named pairs of bars comprising a parallel bar mechanism for controlling the rocking motion of said platen with respect to said base, a pivot point on aeach side of said parallel bar mechanism being formed with a slot aifording.

lost motion as said platenis' rocked about its arcuate'surface, an extension formed on said second pair of bars, and a hook memberiafiixed to said base for engagement withsaid extension for retaining the parallel bar mechanism and platen in a raisedposition. Y

10. A duplicating machine comprising a base, apair'of lugs affixed to said base, apair of links having one end of eachthereof pivoted to one of said lugs, a printing platen having a'cylindrical arcuate printing surface saidv platen being mounted to move over said base with a rocking motion and adapted to have an ink pad and stencil attachedthereto, a pair of arms. formed on the sides of said platen, a pair of barsipivotally connected to the ends of said arms and to the ends of said links remote from the ends thereof pivoted to said lugs, and a second pair of bars substantially parallel to said first-named pair of bars, said second-named pair of bars being pivotally connected at one end of each thereof to the arms on said platen intermediate the arcuate face and 5. The combination with a base plate, of a rock- 7 the end portions thereof pivoted to said first named bars, the other of each of the ends of said second-named pair of bars being pivoted to said links intermediate the end portions'thereof, said links, said arms andsaid first and second named pairs of bars comprising a parallel bar mechanism for controlling the rocking motion. ofv said platen with respect to said base to assure identical alignment and positioning of the stencillimpression during successive strokes of said platen, one of the corresponding members on each side of said parallel bar mechanism being formed at its pivot point with a slot affording lost motion in said parallel bar mechanism as said platen is rocked about its arcuate' surface, means for locking said parallel bar mechanism and printing'platen in' fixed position when the machine isnot in use, an extension formed'on'said'second pair of bars, a hook member affixed to said base for engagement with said extension for retaining the parallel bar mechanism and platen in a raised position while ink is beingapplied to said platen'or while a stencil is being attached thereto.

11. A duplicating machine comprising a base, a pair of lugs afiixedto saidvbase; a pair of links having one end of each thereof pivoted to one of said lugs, a platen having an arcuate printing surface, said platen being mounted to move over said base with a rocking motion and adapted to have a printing stencil attached thereto, apair of arms formed on the sides of said platen, a pair of bars pivotally connected to the ends of said arms and to the ends of said links remote from the ends thereof pivoted to said lugs, and a second pair of bars substantially parallel to said firstnamed pair of bars, said second-named pair of bars being pivotally, connected at one end of each thereof to the arms. on said platen intermediate the end portions of said arms and the arcuate surface thereof, the other of each of the ends of said second-named pair of bars being pivoted to said formed with a slot affording lost motion as said platen is rocked about its arcuate surface, and means for retaining the parallel bar mechanism and platen in a raised position;

12. A duplicating machine comprising abase, a printing platen having an arcuate printing surface, said platen being mounted to move oversaid base with a rocking motion and adapted to have an ink pad and stencil attached thereto, means comprising a pivoted parallel bar mechanism for controlling the rocking motion of said platen with respect to said base, a pivot point on-each side of said parallel bar mechanism being formed with a slot affording lost motion as said platen is rocked about its arcuate surface, and means for retaining the parallel bar mechanism and platen in a raised position.

13. A duplicating machine comprising a base, a pair oflugs affixed to said base, a pair of links having one end of each thereof pivoted to one of said lugs, a platen having an arcuate printing surface, said platen being mounted to move over said base with a rocking motion and adapted to have a printing stencil attached thereto, a pair of arms formed on the sides of said platen, a pair of bars pivotally connected to the ends of said arms and to the'ends of said links remote from r the ends thereof pivoted to said lugs, and a sec ond pair of bars substantially parallel to said first-namedpair of bars, said'second-named pair of bars being pivotally connected at oneend of each thereof to the arms on said platen intermediate the end portions of said arms and the:

arcuate surface thereof, the other of each 'of the ends of said second-named pair of bars being pivoted to said links intermediate the end portions thereof, said links, said arms and said first and second-named pairs of barscomprising a parallel bar mechanism for controlling the rocking motion of said platen with respect to said base, a-

pivot point on each side of said parallel bar mechanism being formed with a slot affording lost motion as said platen is rocked about its arcuate surface.

14. A duplicating machine: comprising a base,

a printingplaten having an arcuate printing surface, said platen being mounted to move over said formed, with a slot affording lost motion as said platen is rocked about its arcuate surface.

15. A duplicating machine comprising a base,

a printing platen having an arcuate printing surface, said platen beingv mounted to move over said base with a rocking motion and adapted to have an ink pad and stencil attached thereto, and means comprising a parallel bar mechanism for controlling the rocking motion of said platen with respect to said base.

16. A duplicating, machine comprising a base, a pair of lugs affixed to. said base, a pair of links having oneend of each thereof pivoted to one of said lugs, a platen having an arcuate printing surface,fsaid:platen being--mounted to move over saidbase with'a rocking motion and adapted to havea printing stencilattached thereto, a pair of arms formed on the sides of said platen, a pair of barslpivotally connected to the ends of said arms 'and'to the ends of said links remote from the ends thereof pivoted to said lugs, and a second pair of bars substantially parallel to said first: named pair of bars, said second-named pair of bars being pivotally connected at one end of each thereof to the arms on, said platen intermediate the end'portions ofsaid arms and the arcuate surface thereof, the other of each of the ends of said second-named pair of bars being pivoted to said links intermediate the end portions thereof, said links, said arms and said first and secondnamed pairs of barscomprising a parallel bar mechanism for controlling the rocking motion of said platen with respect to said base.

17. A duplicating machine comprising a base, aprinting platen having an arcuate printing surface, said platen' being mounted to move over said base with a rocking motion and adapted to have an ink pad and stencil attached thereto, and means comprising a parallel bar mechanism for controlling the rocking motion of said platen with respect to said base, said mechanism including a detachably secured cover plate.

18. The combination with a curved platen formed with end portions, an ink pad of absorbent material mounted on" the convex surface of said platen, a fabric band applied about said ink pad,,and means comprising channel-shaped members affixed to said band for attaching the latter to the end portions of said platen, said band retainingsaid members in position by overlying said members as the latter rock past a dead center position to hold the members hooked over theend portions of said platen.

19. The combination with a curved stencil platen, a fabric ink pad band applied about said platen, and means comprising channel-shaped, hook-like members affixed to the ends of said band for attaching the latter to the edges of 1 said platen, said band retaining said members in I position as said members rock past a dead center position over the edges of said platen.

HUGO H. STOELTING. 

